Ball Activated, Selective Flow Port Downhole Apparatus

ABSTRACT

In one aspect there is provided a selective flow port downhole apparatus comprising a tubular housing with at least one housing port and an interior volume. An actuation mechanism actuates the apparatus between a running position and a ports open position. When in the running position, the housing port is sealed to prevent fluid communication from the apparatus&#39; interior volume through said at least one housing port. When the apparatus is actuated to the ports open position, fluid communication is then established between the inside volume and the outside of the tubular housing, through the housing port. The apparatus may be actuated by one or more balls.

CROSS REFERENCE TO RELATED APPLICATION

This application is a non-provisional application which claims priority to, and benefit of, U.S. Provisional Patent Application Ser. No. 62/878,061 filed Jul. 24, 2019 and entitled, “BALL ACTIVATED, SELECTIVE FLOW PORT DOWNHOLE APPARATUS”, the entirety of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to a downhole tool deployed in a wellbore to replace a burst or rupture disk. More particularly, the invention relates to a ball-activated apparatus allowing an operator to selectively engage, and subsequently disengage, flow into and out of a tubular string's interior.

BACKGROUND OF THE INVENTION

The background information discussed below is presented to better illustrate the novelty and usefulness of the present invention. This background information is not admitted prior art.

During oilfield wellbore completion operations a tubular completion string is run downhole to a desired landing depth, typically adjacent or within a producing formation. A burst or rupture disk is provided on the string's downhole or bottom end, to prematurely prevent fluid in the wellbore from entering the completion string's interior and flow up inside the string to surface.

Burst or rupture disks are commonly incorporated into tubulars, such as casing, drill strings and completion strings. Burst disks typically have a brittle ceramic element or component that is designed to rupture with the application of a predetermined hydraulic pressure. Burst disks are also used in various downhole applications in which the controlled application of pump pressure is used to set or operate downhole equipment, such as packers or plugs.

In an oilfield completion scenario, when the downhole end of the completion string reaches the desired landing depth, hydraulic pressure is applied to the interior of the completion string, the disk is ruptured, and then hydraulic pressure is equalized to allow wellbore fluids to travel up to surface through the completion string's interior. However, in such a case where the burst disk is provided at the downhole end of the completion string, there is a risk that the brittle ceramic element will prematurely burst inadvertently. This is especially of concern if the completion string is shock loaded. Such premature rupturing of the burst disc can even create a blow-out situation, or other safety hazard (e.g. when the interior fluid pressure was not yet equalized). Moreover, once the burst disk is ruptured, there is no easy way to subsequently close off flow of wellbore fluids into the string's interior.

Therefore, what is needed is an apparatus or system that overcomes the disadvantages of these burst discs.

SUMMARY OF THE INVENTION

In one embodiment of the invention, there is provided a selective flow port downhole apparatus comprising a tubular housing with at least one housing port and an interior volume. An actuation mechanism actuates the apparatus between a running position and a ports open position. When in the running position, the housing port is sealed to prevent fluid communication from the apparatus' interior volume through said at least one housing port. When the apparatus is actuated to the ports open position, fluid communication is then established between the inside volume and the outside of the tubular housing through said at least one housing port. The apparatus may be actuated by one or more balls.

In a preferred embodiment of the invention, the actuation mechanism comprises a sliding sleeve located within a sleeve receiving region in the interior volume and the sliding sleeve is actuatable to move within the sleeve receiving region between the running position and the ports open position.

In another embodiment of the invention, the selective flow port downhole apparatus further comprises a normally-closed check valve at a downhole end. When the sliding sleeve is in the running position during wellbore operations and hydraulic pressure inside the interior volume reaches a sufficient threshold to open the check valve, then fluid from the interior volume can exit out of said downhole end.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:

FIG. 1A is a side perspective view of one embodiment of a ball activated, selective flow port downhole apparatus of the present invention;

FIG. 1B is a sectioned, side perspective view of the embodiment of FIG. 1A;

FIG. 1C is another sectioned, side perspective view of the embodiment of FIG. 1A;

FIG. 1D is a side perspective view of some of the interior components of the embodiment of FIG. 1A;

FIGS. 1E and 1F are additional sectioned, side perspective views of the embodiment of FIG. 1A;

FIG. 2A is a sectioned, side perspective view of the embodiment of FIG. 1A shown in the running position, with the housing flow ports closed;

FIG. 2B is a sectioned, side perspective view of the embodiment of FIG. 1A shown in the ports open position, with the housing flow ports opened;

FIG. 2C is a sectioned, side perspective view of the embodiment of FIG. 1A shown in the ports closed position, with the housing flow ports closed; and

FIGS. 3A to 3J are sectioned, side perspective views of the embodiment of FIG. 1A, illustrating the ball activation sequences to activate the apparatus from the running position (FIG. 3A) to the ports open position (FIG. 3F) and subsequently to the ports closed position (FIG. 3J).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is of preferred embodiments by way of example only and without limitation to the combination of features necessary for carrying the invention into effect. Reference is to be had to the Figures in which identical reference numbers identify similar components. The drawing figures are not necessarily to scale and certain features are shown in schematic or diagrammatic form in the interest of clarity and conciseness.

Having reference to one embodiment of a selective flow port downhole apparatus 10 shown in FIGS. 1A-3J, a cylindrical, tubular housing 12 having an exterior housing surface 12E is provided. The tubular housing 12 has uphole and downhole ends 12A and 12B and defines an interior volume 12V. The housing's interior volume 12V further comprises a sleeve receiving region 13, preferably with a substantially consistent cylindrical inside diameter 13I throughout the sleeve receiving region 13. The tubular housing 12 further comprises one or more housing ports 14 formed therethrough. When unblocked or uncovered, the housing ports 14 allow for fluid communication between the housing's interior volume 12V and the outside of the housing 12, as further described below. When blocked or covered, the housing ports 14 are sealed and any further fluid communication between the housing's interior volume 12V and the outside of the housing 12 is prevented, as further described below.

To facilitate inline, sealable connection of the apparatus 10 within, or to, a casing, completion or drill string, or the like, the housing is preferably provided with uphole and downhole collars or connectors 20A and 20B at each respective uphole and downhole ends 12A and 12B. Uphole and downhole connectors 20A and 20B may be treaded connections as is conventional in the wellbore operations industry. In the present embodiment, uphole and downhole collars or connectors 20A and 20B each feature an externally threaded connection (not shown). However, an internally threaded connection will also work to connect the apparatus 10 to a tubular string.

The apparatus 10 further comprises a cylindrical, tubular shifting or sliding sleeve 112 having an exterior sleeve surface 112E. The sliding sleeve 112 is preferably located within the sleeve receiving region 13 of the housing 12 and is actuatable to axially move therein, e.g. between a first running position (see FIG. 2A), a second ports open position (see FIG. 2B), and a third ports closed position (see FIG. 2C).

The sliding sleeve 112 has uphole and downhole ends 112A and 112B and defines an interior volume 112V. The sleeve's interior volume 112V further comprises a ball receiving region 113, preferably with a substantially consistent cylindrical inside diameter 113I throughout the ball receiving region 113. The sliding sleeve 112 further comprises one or more sleeve ports 114 formed therethrough. When unblocked or uncovered, the sleeve ports 114 allow for fluid communication between the sleeve's interior volume 112V and the outside of the sliding sleeve 112, as further described below.

The sliding sleeve 112 further comprises a first ball stop or shoulder 116 at an axial position closer to the downhole end 112B. Preferably, first ball stop 116 is configured to sealably receive a first ball 200 having a first diameter 200D. More preferably, the sliding sleeve 112 further comprises a second ball stop or shoulder 118 at an axial position closer to the uphole end 112A. Even more preferably, second ball stop 118 has an inside diameter 118I that is larger than the first ball's first diameter 200D, and the second ball stop 118 is configured to sealably receive a second ball 210 having a second diameter 210D. Yet even more preferably, the second diameter of the second ball 210 is larger than the first diameter 200D of the first ball 200, and larger than the second ball stop's inside diameter 118I. The first and second balls 200, 210 are provided to the apparatus 10 via conventional ball dropping means, though the interior of the completion string, or other tubular member to which the apparatus is sealably connected.

Preferably, the various components of the apparatus 10 are made of metal, steel or any other suitable material that provides adequate strength, durability, sealability and rigidity to support the various loads, pressures and forces that may be encountered in a downhole, wellbore environment. More preferably, the first and second balls 200, 210 are made from metal, as are the first and second ball stops 116, 118. As such, when first and second balls 200, 210 sealably engage against their respective ball stops 116, 118, the seal created is a metal-on-metal seal. Advantageously, a metal-on-metal seal is inherently stronger than the ceramic burst disks and less likely to suffer from breakage or inadvertent failure; and the apparatus is therefore significantly reduces the risk of blow-outs as compared to conventional burst disks.

When in the apparatus 10 is in the running position, the sliding sleeve 112 is preferably maintained in a first axial position within the sleeve receiving region 13 so that the sleeve 112 is closer to the uphole end 12A of the apparatus 10, and so that the housing ports 14 are fully blocked and sealed by the sleeve's exterior surface, thereby preventing any fluid communication from the inside volume 12V through the ports 14 and to the outside of the housing 12 (see FIGS. 2A and 3A). Preferably the sliding sleeve 112 is secured in this position by means of a first set of set screws 40. Preferably the first set of set screws 40 are provided through the housing 12 and are screwed into the sleeve's exterior surface 113 (see FIG. 1D). The first set of set screws 40 are designed to break or shear upon a first threshold force, thereby freeing the sleeve 112 and allowing it to travel axially along the sleeve receiving region 13 towards the downhole end 12B (see FIGS. 2B and 2C).

More preferably, a second set of set screws 50 are provided to limit axial travel of the sleeve 112 to the ports open position (see FIG. 2B). Set screw channel guides 60 are preferably provided to capture the ends of the second set of set screws 50. Preferably, set screw channels 60 each have a shearing surface 62 to cause sleeve 112 to shear the second set of set screws 50 upon a second threshold force, which is preferably higher than the first threshold force. Once the second set of set screws 50 have sheared, sleeve 112 is able to continue axial travel in the sleeve receiving region towards the downhole end 12B and into the ports closed position (see FIG. 2C). The first and second threshold forces can be determined by, and/or related to, a fluid pressure within the interior volume 12V as may be applied by fluid within the interior of a tubular completion string (not shown) to which the apparatus 10 is attached. Such interior volume fluid pressure can then be created by a surface-based pump, pumping fluid (e.g. drilling mud) down the interior of the completion string, through the uphole end 12A and into the interior volume 12V.

During operations, a tubular completion string (not shown) may be run downhole to a desired landing depth, typically adjacent or within a producing formation. The apparatus 10 is provided to the tubular completion string, in place of a burst or rupture disk, preferably on the tubular completion string's downhole or bottom end. The apparatus is set (or actuated) to the running position so as to prematurely prevent fluid in the wellbore from entering the completion string's interior and flow up inside the string to surface (and vice versa). If a check valve 30 is present (as further described below), the check valve 30 will also act to prevent fluid in the wellbore from entering the completion string's interior. Other than the housing ports 14, and any check valve 30, it is to be understood that the apparatus 10 will seal off the tubular completion string and prevent wellbore fluids from entering and/or exiting the string's interior (similar to how a burst or rupture disk would seal off such string).

During operations, a first ball 200 may be provided into the tubular completion string (e.g. at the surface end of said string) and travel downhole towards the sliding sleeve's interior volume 112V by entering at the uphole end 112A (e.g. see FIG. 3A). That first ball 200 preferably has a diameter sufficiently small to allow it to travel axially along the interior volume 112V, through and past the second ball stop's inside diameter 118I and toward the downhole end 112B (e.g. see FIG. 3B) to sealable engage against the first ball stop 116 (e.g. see FIG. 3C).

Once the first ball 200 sealably engages against the first ball stop 116, a sufficiently strong hydraulic force may be applied to the interior volume 112V, overcoming the first threshold force and causing the one or more first set screws 40 to break, release the sleeve 112 from the housing 12 and cause the sliding sleeve 112 to move axially towards the downhole end 12B and actuate the apparatus into the ports open position (see FIG. 3F).

When this happens, the one or more sleeve ports 114 are substantially aligned and paired with the one more housing ports 14, so as to establishing fluid communication between the inside volume 12V and the outside of the housing (and the annular space between the apparatus 10 and the wellbore or casing). Paired ports 14, 114 may partially align (FIG. 3E) or fully align (FIG. 3F). It will be appreciated that even when partially aligned, fluid communication between the interior volume 12V and outside of the housing will be established.

During operations, a second ball 210 (preferably having a larger diameter than the first ball) may also be provided into the tubular completion string and travel down to the sliding sleeve's interior volume 112V by entering at the uphole end 112A (e.g. see FIG. 3G). That second ball 210 may then travel axially along the interior volume and have its diameter sufficiently large to seal against the second ball stop 118. Once the second ball 210 sealably engages against the second ball stop 118, a sufficiently strong hydraulic force may be applied to the interior volume 112V, overcoming the second threshold force and causing the one or more second set screws 50 to break (e.g. due to shearing surfaces 62 shearing second set screws 50), allowing the sleeve 112 to continue to move axially towards the downhole end 12B and actuate the apparatus into the ports closed position (see FIG. 3J).

When this happens, the one or more sleeve ports 114 are substantially misaligned with the one more housing ports 14, so as to stop any fluid communication between the inside volume 12V and the outside of the housing (and the annular space between the apparatus 10 and the wellbore or casing).

Suitable seals such as o-rings 70 may be provided between the sliding sleeve 112 and the housing 12 so as to only allow fluid communication between the inside volume 12V and the outside of the housing 12 through paired ports 14 and 114 when the paired ports 14, 114 are partially aligned (FIG. 3E) or fully aligned (FIG. 3F), and to prevent fluid communication between the inside volume 12V and the outside of the housing 12 when the sleeve ports 114 are misaligned with the housing ports 14.

Alternatively, in another embodiment (not shown), the sleeve 112 doesn't have any sleeve ports 114, but is sufficiently short to have its uphole end 112A move past housing ports 14 when actuated to the ports open position. Such an embodiment would not provide for a subsequent ports closed position. However, such an embodiment will act very similar to a burst disk, preventing fluid communication to the interior of the completion string when in the running position, and then providing fluid communication to the interior of the completion string once actuated.

The embodiment of the apparatus 10 shown in FIGS. 1A-3J preferably further comprises a conventional check valve 30 at the downhole end 12B. The check valve 30 preferably comprises a metal ball 32 biased against a ball sealing surface 34 by means of a spring 36, wherein a metal-on-metal seal is created that is normally closed and sealed (see FIG. 1B), unless a threshold hydraulic pressure is reached within the interior volume 12V. During wellbore operations and once the threshold hydraulic pressure is reached, the ball 32 is pushed against the spring 36, overcoming the spring's bias, and the ball 32 is moved away from the sealing surface 34 and the check valve 30 opens, releasing hydraulic fluids from the interior volume 12V out through an opening 38 at the downhole end 12B in a conventional manner.

Advantageously, when the apparatus 10 is in the running position, and hydraulic pressure inside the interior volume 12V reaches the threshold, fluid from the completion string's interior can be pumped out of the downhole end 12B so as to clean-out, or circulate out any sand or other debris from the wellbore, i.e. up to surface along the annulus between the completion string and wellbore or casing. Such pumping or circulation, during running of the completion string is not possible with conventional burst discs.

It should also be understood that the apparatus 10 can function without a check valve 30, e.g. by having its downhole end 12B fully sealed or closed. While such embodiments of the apparatus 10 will not allow for sand or other debris to be easily cleaned out from the wellbore, such apparatus 10 will still provide actuatable fluid communication between the interior volume 12V and the exterior of the apparatus through one or more housing ports 14 (as described above).

Those of ordinary skill in the art will appreciate that various modifications to the invention as described herein will be possible without falling outside the scope of the invention. In the claims, the word “comprising” is used in its inclusive sense and does not exclude other elements being present. The indefinite article “a” before a claim feature does not exclude more than one of the features being present. 

The embodiments of the invention in which an exclusive property or privilege is being claimed are defined as follows:
 1. A selective flow port downhole apparatus comprising: a tubular housing having a downhole end, at least one housing port and an interior volume with a sleeve receiving region; a sliding sleeve located within the sleeve receiving region and actuatable to move between a running position, a ports open position, and a ports closed position; a check valve at a downhole end of the apparatus; wherein, when the sliding sleeve is in the running position during wellbore operations, the at least one housing port is sealed to prevent fluid communication from the interior volume through said at least one housing port; wherein, when the sliding sleeve is in the running position during wellbore operations and hydraulic pressure inside the interior volume reaches a threshold sufficient to open the check valve, fluid from the interior volume can be pumped out of the downhole end; wherein, when the sliding sleeve is in the ports open position, fluid communication is possible between the interior volume and the outside of the tubular housing through said at least one housing port; and wherein, when the sliding sleeve is in the ports closed position, any fluid communication that may have been possible through said housing port is stopped.
 2. The selective flow port downhole apparatus of claim 1 wherein the sliding sleeve is actuatable by means of at least one ball.
 3. A selective flow port downhole apparatus comprising: a tubular housing having at least one housing port and an interior volume; an actuation mechanism to actuate the selective flow port downhole apparatus between a running position and a ports open position; wherein, when the selective flow port downhole apparatus is in the running position, the at least one housing port is sealed to prevent fluid communication from the interior volume through said at least one housing port; and wherein, when the selective flow port downhole apparatus is actuated to the ports open position, fluid communication is established between the inside volume and the outside of the tubular housing through said at least one housing port.
 4. The selective flow port downhole apparatus of claim 3 wherein the actuation mechanism comprises a sliding sleeve located within a sleeve receiving region in the interior volume, said sliding sleeve actuatable to move within the sleeve receiving region between said running position and said ports open position.
 5. The selective flow port downhole apparatus of claim 4 wherein the sliding sleeve is actuatable by means of at least one ball. 